Sanitary liquid trap



June16,1931.

v R. A. GREENWOOD SANITARY LIQUID TRAP Filed Aug. 9. 1930 W/Mrae fry a substantially U- h t is reduced b l t hi h the bye-pass conne I liquid from i '30 pressure differences.

are liquid Patented June 16 1931 ROBERT ARTHUR, eaannwoon, or cnnnsna, LONDON, ENGLAND SANITARY LIQUID mm? 7 Application filed August 9, 1930, Serial No.

This invention comprises improvements in or relating to sanitary liquid traps of the type (e. g., known in the trade as S1, halfbag traps) in which a liquid seal is provided in haped'portion of the trap and a bye-pass is arranged to communicate between a point below the normal level of the seal on the inlet branch of the aforesaid U-shaped portion and a point above theover- '10 flow level on the outlet branch.

In a trap of the above type the bye-pass aforesaid is provided for the purpose of preventing the siphoning away of the liquid i seal when the pressure on the outlet side of that on the inlet side. When the pressure on the outlet side of the trap is so reduced, the sealing liquid 7 will be drawnground the bend of the U until the level in the inlet branch falls to the point ction (normally I submerged) is uncovered whereupon air a will be drawn through the bye-pass and, exerting pressure'on the liquid on the outlet branch" of the trap, will prevent the sealing being completely discharged. It is one object of the invention to provide means whereby'an adequate supply of liquid for resealing the trap is stored in-it after the discharge of some ofthe liquid caused by The invention comprises a sanitary liquid trap of the type described in which, for the purpose specified, the outlet. branch of the U-shaped portion of the trap is arranged to communicate with a laterally offset liquid storage chamber located wholly to one side of the said outletbranch, and the by-pass communicates with the said chamber at a s 40 point between the middle and the overflow end thereof, and preferably near the middle; The liquid storage chamber aforesaid may be formed integrally with the outlet branch ofthe U-shaped portion of the trap, or it may '45 be detachably secured thereto,

for example, by means of screw-imions, sockets or the like. According to a feature of the invention, the byepass pipe may 'debouch intothe liquid stora e chamber at such an angle 'thatthe entering the chamber through said I inlet side falls to uncovered and air;

equalize then adjusts itself to about theilevel-z-zb If now-further suctiontakes place b'efore the jthe bye-pa Asp 474,275, and in s am Africa June 4,:1930.

In this embodiment; of invention, the 1 inlet is ata and the outlet at -b.' The trap proper is at 0, and cl represents the bye pass from the inlet branch of the trap tothe upper part 0 The f-the horizontal chamber e;

bye-pass 1 isarran'ged to communicate bye-pass is directed 'awayifromtheoverfiow endofthetrap. v i S, P and with the chamber e at or'near-thei middle thereof,;-in order to reduce the likelihoodof 1 the water in the chamber being splashed over into the outlet pipe when suction ofair takes place through thebye-pass d.

After the trap has been flu hed,it is filled with water up to'the level If suction lace at the outlet eb -the watera-overtakes p d the bend f until the level on the flows rou-n when the inlet endtof the by-pass becomes thoughthe bye-pass until the pressure is d. The water remaining inthe-trap;

trap has been reflushed, the water is again drawn up into the chambere until the inlet end of the bye-,passis,uncovered; but no wa-- -ter r:v only a negligible; quantity ofw'water 1 which may be splashed over,

stamping or drawing, and a scre'w-plugmay be 'fitte'd to the trap tobe cleaned. -The trap may be constructed of any suitable material suchlas lead, iron,;brass, earthenware or the like;

It {will be observed f'that the inlet end of v ss is only uncovered when suction occursatthe outlet 5, and that consequently anadequate seal is always maintained. j t

ecial advantage of sanitary traps according to the invention is thate'the quantity abontthedotted line bottom thereof to vallow the is drawn from the inlet over-flows round ethe bend f. t Thetrap illustratedin the drawings'may conveniently be formed by casting,

" f water necessary in the U shaped-portiontof 9 the trap in order that the sealing level may be to the flow of the liquid, Whereb maintained after a portion of the water has been discharged by pressure differences is considerably less than in the case of the traps hitherto employed. It is essential that a sanitary trap should be self-cleansing and it is evident that the trap according to the invention fulfills this condition especially as regards the bye-pass connection, through which both air and water are drawn with considerable force. thereby producing a thorough scouring effect.

A further special advantage of the construction of the sanitary liquid trap illustrated in Figure 1 of the accompanying drawing is that the bye-pass debouches into the liquid storage chamber at such an angle that the tendency of the liquid drawn throughthe bye-pass to splash over the bend f to Waste is greatly reduced, with the result that a smaller depth of water may be provided in the U-bend while still ensuring that an adequate sealing level is maintained after suction has taken place. This is an advantage from the hygienic point of view, owing to the improved cleansing effect when the trap is flushed.

In an alternative construction of the trap illustrated in Figure 1.- the radius of the upper portion of the bend of the outlet branch where it enters the chamber e may be reduced.

It is found that in this case the tendency of the liquid to siphon over to waste when suction occurs is still further reduced;

The section of the trap according to the invention is preferably substantially circular,

as illustrated in Figure 2,'but it is within the invention to employ a substantially square,

- oval, triangular or other suitable section.

The trap may be formed in one piece from a metal, such for example as lead, by drawing, casting, stamping, or by a similar process, but

' it may, if desired, be built up of several elements detachably secured together, for example, by means of screw-unions, sockets or the like. Thus, the bye-pass may be detachable at one or both ends from the body of the trap,

and the U-shaped portion of the trap may be formed of two-sections united together by a suitable union. screw unions may conveniently be provided on the inlet and outlet branches of the trap, to enable the latter to be attached to the fitting with which it is to be used, and to the waste pipe. I

The trap may also be made of earthenwar or other suitable material.

What I claim is A sanitary liquid trap including a laterally o fiset liquid storage chamber communicating with and located whollyto one side of the outlet branch of the trap proper, and a by-pass communicating with the chamber adjacent the overflow end of such chamber, the exit end of the by-pass inclining at an angle chamber.

ROBERT ARTHUR GREENWOOD. 

